Duplex and multiple action plunger pump



Feb. 3, 1931. w. E. sPLAlN DUPLEX AND MULTIPLE ACTION PLUNGER PUMP [www 1111 IM@ l l l l l l |||a y 65W NToR. M am'. BY ,L M ATTORNEY. l

Patented Feb. 3, 1931 WALTER E. SPLAIN, o1" TERRACE PARK; omdnssrenon rowrtmeian emscnxyon czrivrenvlviitx:i,'o1-iroV f DUPLEX AND MULTIPLE ncrrontPILUNGER EUMB` Application led September 1S, k1928. Serial No. 306,633.

My invention relates to multiple cylinder plunger pumps, and particularly to such pumps as are required for the dispensing of motive and lubricating oils.

It is the object of my invention to provide a multiple cylinder, piston type pump having interconnecting ports extending from the dis-V ,charge side of each cylinder into the suction side of another. I find that With such .an arrangement each reciprocating piston stroke appears lto exhaust a volume of iiuid equal to the cubical capacity of the length of the stroke of the piston, times thev area of the respective cylinder in Which the piston is operating.

YIn duplex pumps, for example, in the past there have been two cylinders each With a piston in it, and a rocking lever With means for actuating it. The pistons have been so arranged on the lever that as one descends in one cylinder, the other ascends in the other cylinder. Each cylinder goes through a cycle of operations of intake from the suction line, with the piston ascending in the cylinder, then change through a valve in the piston from one side of the piston to the other, during the descending stroke of the piston, and then discharge from above the cylinder on the next following ascending stroke. In contrast to the usual type of pump constructed accordingly7 it is my object to provide a pumpy in which each cylinder has an intakevalve at one end, and an outlet valve at the other, with no valve in the' piston, but with a bypass or port from the suction end of each cylinder to the discharge end of another cylinder so that each reciprocating movement of each piston will cause the displacement of the volume of one intake stroke' into the discharge. e

Referring to the drawings in which I have illustrated a preferred form of duplex pump embodying my invention: Y

Figure l is a side elevation With the upper part of the pump shown in section.

Figure 2 is a sectionalview of4 the: pump] taken in a vertical p lanefat 'an angle of9`f0 degrees from that at which thevievvin-Figure 1 Was taken. VVi

Generally indicated at l'isithepulinp casing which Yas shown has anintake port 2. inthe v'Iier ein stares PATENT cept-ICE;

end shovvn tovvards'thebottom inthe draW- ing. The discharge port Sis'atfthe top of l the casing. The casing is provided With two bored cylinders 4 and 5', with pistons @and 7 which arel mounted on l piston rods. 8 and 9 respectively for movingthepistons through the cylinders. A: roc-king levermounting7 .a's indicated.r at 10',v is provided which. may be rocked hack and forth by means-of' an operata housingeliminates .the frictional loss of Y packing 'glands Whichlwould berequired were the rods 8 and 91to extend through thecasing.

The top housing is provided With divisional compartment Walls, the Wall.` 1:8; extending Vd'ovvn frorn'fA the'V top-andthe WallLIQfeXtend- 'ingup ffrom" the` bottorn,' so that by; drilling a hole-.through the housing in thefposition .1 indicated: a-.tight Vjoint is: formed as soonas the shaft 2is" inserted-and as soonas the shaft has a rotatable bearing?, against theV Walls 18 andl; The shaftwvill have packing glands to; preventleakage'i along itsk axial A portions Where it extends through the hous- Y ing,` but the Vfrictional loss in such apackingv gland? is -much less than n Wouldfhe required :Were VVthe lpiston rods' to extend' through packed glands. i Therocking handle 'lll' Wit-h VWhich the fpump isV 'operated isfmountedY di I rectlyon the shaft 20'.A f L n i Extending throughi hefwall separatingrth'e pistons I have provi'dedbypassesthrough 60 ing arm 11, Eachtcylinder has; anffintake valve 12of desired'typeat the bottom end,

` ieV pressed below the piston 7, however, will be 'luid' discharged.

which the liquid being pumped will tend to move, during the compression stroke of the piston on the left, as shown in Figure 2, from above the piston'? downwardly into the space below the piston 6 along the lines of the ar- Yrows bn-a. The current along the lines a-a will be scarcely appreciable beingcaused only by the difference in the height or the liquid above the piston '.7 above the height of the liquid below the piston 6. The liquid comorced under full pressure upthrough the by-pass extending from below the piston 7 to above the piston Galong the lines indicated Vby the arrowsb-b.

The Voperation of my duplex pump is parf n ticularly eective :for a measuring device, as"

it provides with each reciprocating stroke the discharge of a quantity from the pumpA equal to the volume retained in each cylinder. One complete rocking'operation of the lever l appears to cause the discharge of the entire volume of fluid retained within the cylinders, apparentlybecause the downward stroke of onefpiston will force that liquid below the piston out through the by-pass and the discharge end of the other cylinder. There apof'cylinders and a pair of pistons without Y rings reciprocable therein, piston rods for said pistons, and means disposed within the housing for actuating said piston rods, said housing being divided by walls into two discharge compartments 'with a shaft carrying Y said piston rod actuating means said walls and shaft forming a barrier between said two compartments, said housing having passages extending from the discharge side of each cylinder to the suction side of the other. c

WALTER E. SPLAIN.

pears to be no lost motion in the pump, and Y forsuch equipment as oil dispensing Yapparal tus where the requirements are for small Y pumps, there is economy of manufacturing expense, simplicity of` operation, and accuracyv of measurement oi the volume of liq- A similar type of structure may be used for a very effective air compressor. It twill be obvious that I have shown a very simple construction, but I do not Vwish to be limited becausev ofthis fact, to the specicexample of my invention shown. Mechanical modiiications which will readily occur `to those skilled in the art, I consider within the Vscope of my invention.

Having thus described'my `invention what i I claim as new and desire to secure by Letters Patent is Y Y n 1.*-A duplex pump having a casing containing apair of cylinders and a pair of reciprocating plungers, eachY cylinder having .a

piston rod, a lever mounted within the pump i casing t0 which saidpiston rodsfare connected, and a rotatable shaft extending Y r through the casing onwhich shaftsaid lever isA mounted, a housingfenclosing said lever L Vforming discharge zones for said cylinders,

said housing being divided by a branch wall l extendingdownwardly and a branch wall eX- i tending upwardly, which when said rotatable shaft is inserted within the housing provides asealed barrier between the respective'discharge YZones of each cylinder, and said cylinders having intersconnecting by-passes eX- the suction-side of the other. Y.

2. In a piston type pump, a housing, a pair Vtending from the discharge side "of each to ioo 

